Computed tomography findings of pathologically proven pulmonary infarction associated with bronchogenic carcinoma are reported for two patients. In one case, the infarction was demonstrated as a well-defined pleura-based large nodule in the peripheral portion of the same lobe of the tumor. The nodule had a smooth, convex border and a linear strand from the apex of the lesion toward the hilum. The obstruction of the subsegmental pulmonary artery due to tumor invasion was considered the cause of pulmonary infarction. In the second case, the infarction was demonstrated as a rapidly appeared, pleura-based consolidation in the same lobe of the tumor with a blurred border. Obstruction of the pulmonary vein by a tumor might have played an important role in the development of the pulmonary infarction in association with a large pulmonary artery obstruction. We conclude that pulmonary infarction should be considered as a differential diagnosis when peripheral pulmonary nodules or masses are located in the same lobe as the primary cancer.